1. Technical Field
The invention generally relates to automated milking apparatus and, more particularly, to a restrictor for controlling the “A” phase or the “C” phase of the pulsation process. Specifically, the invention relates to a restrictor that may be incorporated into the pulsation process to slow the “C” phase of the pulsation process to improve milking efficiency. One manner of positioning the restrictor is to splice the restrictor into the pulsator tube.
2. Background Information
An example of an automated milking machine is indicated generally by the numeral 1 in FIG. 1. Machine 1 is one example of a configuration known in the art to extractor milk from dairy animals. Milk extraction typically occurs in a milking facility where dairy animals are positioned in milking stalls. Milking machine 1 may be provided for each milking stall. Machine 1 generally includes a claw 2, multiple teatcups 3, a long milk tube 4, a long pulsator tube 5, and a pulsator 6. Claw 2 is an assembly that connects short pulsator tubes 7 and short milk tubes 8 from teatcups 3 to long pulsator tube 5 and long milk tube 4. A milk bucket 9 is provided to accumulate the milk extracted from the animal. A vacuum source 10 is fluid communication with machine 1.
As shown in FIG. 2, each teatcup 3 includes a rigid outer shell 11 that holds a soft milking liner or inflation 12. The annular space between shell 11 and liner 12 is a pulse or pulsation chamber 13. Liners 12 are attached to the teats 14 of a dairy animal to perform the milking process. The milking process is driven by applying a cyclic vacuum to pulsation chamber 13.
During milking, liner 12 is subjected to a milking vacuum 15 through short milk tube 8. FIG. 3 depicts the following pulsation process graphically. Pulsation chamber 13 is subjected to a pulsating vacuum that varies between approximate atmospheric pressure and a vacuum pressure that approximates or is greater than the milking vacuum applied to liner 12. The pulsating vacuum is controlled by pulsator 6. Pulsator 6 has a four-phase pulsation cycle defined by (i) an opening phase (the A phase) during which the pulsation vacuum 16 increases from atmospheric pressure to the milking vacuum level and liner 12 moves from a closed position to an open position (the pressure of liner 12 is indicated on the graph with reference line 17), (ii) an open phase (the B phase) during which the pulsating vacuum has reached its maximum level, which is substantially equal to the milking vacuum level, liner 12 is in an open position allowing milk to flow from teat 14, (iii) a closing phase (the C phase) during which the pulsating vacuum decreases from about the milking vacuum level to the atmospheric pressure and liner 12 moves from the open position to the closed position, and (iv) a closed phase (the D phase) during which the pulsating vacuum is equal to the atmospheric pressure and inflation 12 is in a closed position stopping milk flow from teat 14. The above action of pulsator 6 is referred to herein generally as the “pulsation process.” The above phases are referred to as phase A, phase B, phase C, and phase D.
As shown in FIG. 2, pulsator 6 applies the different vacuum pressures of phases A-D to chamber 13 through a long pulsator tube 5 and a short pulsator tube 7. Tubes 5 and 7 are typically flexible tubing.